Induced responses in the neotropical shrub Bauhinia brevipes Vogel: does early season herbivory function as cue to plant resistance?
2011
Cornelissen, Tatiana | Fernandes, Geraldo Wilson | Coelho, Marcel Serra
Models of plant phenotypic plasticity suggest that past or current environment provide information about future environments, and plants respond to past or current herbivory by increasing their resistance to herbivores. In this study, we determined whether damage to Bauhinia brevipes leaves caused by free-feeding and galling herbivores early in the season predicts the frequency of attack throughout the season, examining the occurrence of induced responses and resistance during 2 years in 50 individual plants. We found that damage early in the season was a reasonable predictor of the number of galls and scars that would be initiated throughout the season. Galling attack rates were significantly higher in 1997 than in 1998, but the opposite pattern was observed for attack rates by free-feeding herbivores between years. Also, leaf nutritional quality differed significantly among three sampling dates, and a trend for an increase in tannin concentration was observed from the beginning to the end of the season. A negative correlation was found between the number of scars caused by chewing herbivores at the end of the season and tannin concentration, but there was no relationship between tannin concentration and percentage of galled leaves or number of Contarinia sp. galls. Furthermore, likelihood of gall survivorship was inversely related to the number of galls recorded early in the season in both years—an indicator of induced plant resistance. This study suggests that early season damage was a reasonable predictor of damage caused by two types of herbivores throughout the season, and that in systems where herbivory is fairly unpredictable within a short temporal scale; the expression of induced responses and resistance is favored.
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